Sun rooms or solariums are well-known in the art. Generally, such sun rooms are mounted or attached onto homes or other existing structures in order to provide light and airy additional rooms for family living or for seating for restaurants and the like. Typically, such sun rooms are generally box-like in configuration. One particularly popular variety of sun room, though being generally box-like in shape, includes a curved transition roof portion which gives the sun room a very attractive appearance. Such sun rooms are generally framed in aluminum wherein the frame supports glass sections not only for the sides and front but also for the roof so that the feeling obtained is a light and airy feeling of openness. One of the disadvantages of such sun rooms is energy inefficiency. Because the sun rooms are virtually all glass, there is no insulation and thus heat transfer from a very hot or very cold outside temperature causes the rooms to be either uncomfortable or require extensive cooling or heating. One solution to the heat transfer problem is to make the roof entirely out of insulated materials such as insulated panels. However, such rooms are made with flat roofs which darken the room and remove the curved glass roof to front wall transition section thus eliminating much of the attractiveness of the room. Insofar as known, no one has been able to provide a sun room that includes both insulated panels in the roof and the attractive curved transition from roof to front wall that is so popular today.